Can you educate me about BEARINGS?

HMF

HMF

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Can you educate me a bit about ball bearings?

A lot of restorations of our machines require removal and replacement of bearings.


First: What TOOLS do you need to properly repair and replace bearings?


Second: Where do I buy then and how do I pick the right ones among the many options?

What is the difference, for example between "Single Row", "200 series", "deep groove wide cup" and "deep groove two felt"?

Are these all sealed bearings?

Finally, are there any bearings made in the USA still, or recommended bearing sources?

Thanks!


Nelson
 
Mumbles -

Thanks for that info! Looks like some good reading there. . .
 
Thanks, again - I just sent in a request for that video. I replaced the spindle bearings on my little Rambold turret lathe, and working without much info, I felt a bit lost in the process. Did get the job done and it runs as true as I can measure, so I figure that's good enuf for me, but next time I get into a similar job, I'd like to be better informed.
 
Here are some sites that might help:

http://www.accuratebearing.com/

http://www.ahrinternational.com/bearing_interchange.htm

http://www.ahrinternational.com/HYATT-BALL-BEARINGS_nomenclature.shtml

http://www.bearingsdirect.com/store/index.php?l=product_list&c=96

http://www.drillspot.com/products/651205/ntn_88016_2as_agricultural_radial_ball_bearing?s=1

http://shop.electricvehicleswa.com/...hp?main_page=product_info&products_id=135

Bearing numbers are universal for the most part. The 5 indicates an outside diameter the 04 the inside diameter. The 88 is a mfg prefix indicating something special about the bearing. A suffix letter or letters will indicate seal or shield identification. One letter a single shield or seal a double letter will indicate a double seal or shield. So that being said all 504 bearings will be the same metric OD and ID. ND or New Departure is the initials of the bearing Mfg like NSK, SKF or FAG ete. A good bearing house will be able to tell you what the 88 means in your bearing number. It could mean an extended inner race or some other special feature on the bearing.

In modern bearings the lack of any suffix means there are no seals or shield. Before 1950 bearing numbers were not quite so universal and I have found in older machines that there can be some odd bearing suffix or preffix letters or numbers, but still they will be metric in dimension and the three numbers will indicate what size of bearing it is. So if the bearings you took out of the lathe have the same width for the inner ring as does the outer ring or race you have a standard bearing. The 6 in the number indicates a Conrad style of bearing. This means its a medium duty bearing with deep grooves and will carry the same auxiliary load in either direction. These are the most common bearing you will find. You can get this bearing at a good auto parts store or a bearing house you mite even find them at a well stocked True Value hardware store.

Now a lot of bearings in these smaller sizes will also have the letters EM on the package. The EM means the bearing is suitable for Electric Motor service. Electric motor bearings have just a little more internal running clearance than standard bearings. An EM bearing will work just fine in your application.

New Departure 88016 and 88505 bearings like those used on a South bend Drill Press are double sealed bearings with felt type seals protected by metal shields. That is why the inner race has the extra width. The 88016 bearing is 16 x 35 mm and the 88505 bearing is 25 x 47 mm. Both are light series bearings.


 
I saw one of those "how it's made" programs about ball bearings. At the end, the tour guy said all the different grades were made on the same equipment, and were sorted from the batch by testing at the end.

Maybe that explains what my friend said many years ago. He worked as a tool and die maker for Hewlett-Packard down the street from here. In 1975 he made us this cool fret slot cutting tool:




I recall him saying that he had to sort through and measure dozens of bearings to get a pair with less runout.

Puts me in mind of a major Spanish classical guitar factory. If they needed more "second grade" instruments, and had only first quality ones, they'd downgrade the label and sell some of 'em for less.
 
Tell us more. Looks like the channel with the fret index holes comes off and you stick a different one on for whatever scale length you want to cut? That's too cool.
 
That's right, there are interchangeable index plates for the various fret scales. When Thom made this tool, he was working in a state-of-the art facility that used punched paper tape to guide the NC machines.

Here are a couple more shots:




Now that I can do my own machining and have a mill with DRO, I can drill my own slides with precision. In fact, this year I just finished making an entirely new slide so I could handle longer fingerboards for electric bass. As our shop has grown, we've added new folks in the repair department, and some of them want to make stuff that's bee outside my personal interest. So we find ourselves cutting scales as short as 12.5" for ukulele and as long as 35" for bass.
 
I should have taken an interest in home machining when I was working for HP (22 yrs). I was often in the Bay Area - I may even have been in your store at some point. So many things to be interested in and so little time.....

That's a neat machine.
 
Digging this one up from the grave. :)

So other than obvious "that don't sound good" sounds coming from the bearings, or hard to turn shafts/axles, or missing balls (sounds painful!), how does someone know when/if they need to replace bearings?
 
Is it me or is there a post or two missing? Nelson asks about bearings, Frank thanks someone for a video that is not mentioned nor is there a post from the person he thanks. Then Nelson answers his own question...

Chuck
 
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